Sample manager, system and method

ABSTRACT

A method of aspirating a sample includes moving a sample needle downward to a first position so a tip of the sample needle touches a bottom of the sample container, determining that the tip of the sample needle is in the first position where the sample needle is in contact with the bottom of the sample container, after the determining that the tip of the sample needle is in contact with the bottom of the sample container, incrementally moving the sample needle upward from the first position, determining the sample needle has moved a predetermined distance upward from the first position and then aspirating a sample in the sample container.

RELATED APPLICATION

This application is a non-provisional patent application claimingpriority to U.S. Provisional Patent Application No. 63/323,255, filedMar. 24, 2022, titled “Sample Manage, System and Method,” which isincorporated herein by reference.

FIELD OF THE INVENTION

The invention relates generally to liquid chromatography systems. Moreparticularly, the invention relates to liquid chromatography samplemanagers, and associated systems and methods.

BACKGROUND

Chromatography is a set of techniques for separating a mixture into itsconstituents. For instance, in a liquid chromatography system, a pumptakes in and delivers a mixture of liquid solvents to a sample manager,where an injected sample awaits its arrival. In an isocraticchromatography system, the composition of the liquid solvents remainsunchanged, whereas in a gradient chromatography system, the solventcomposition varies over time. The mobile phase, comprised of a sampledissolved in a mixture of solvents, passes to a column, referred to asthe stationary phase. By passing the mixture through the column, thevarious components in the sample separate from each other at differentrates and thus elute from the column at different times. A detectorreceives the elution from the column and produces an output from whichthe identity and quantity of the analysis may be determined.

Prior to being provided into the liquid chromatography system, thesample may be provided to a sample manager. The sample manager may beconfigured to prevent the sample from degrading or becoming otherwisedamaged while providing the sample into the liquid chromatographysystem. Sample managers are regularly interacted with by technicians andas such must be user friendly, dependable, accurate, reliable,serviceable, and cost effective. Improved sample managers, systems andmethods, would be well received in the art.

SUMMARY

In one embodiment, a method of aspirating a sample includes moving asample needle downward to a first position so a tip of the sample needletouches a bottom of the sample container; determining that the tip ofthe sample needle is in the first position where the sample needle is incontact with the bottom of the sample container; after the determiningthat the tip of the sample needle is in contact with the bottom of thesample container, incrementally moving the sample needle upward from thefirst position; determining the sample needle has moved a predetermineddistance upward from the first position; and after the determining thesample needle has moved the predetermined distance upward from the firstposition, aspirating a sample in the sample container.

Additionally or alternatively, the method further includes before themoving the sample needle downward to the first position so the tip ofthe sample needle touches the bottom of the sample container, using anoptical sensor in determining a starting position of the sample needlesystem relative the sample container.

Additionally or alternatively, the method further includes using anoptical detection system in determining that the sample needle has movedthe predetermined distance upward from the first position.

Additionally or alternatively, the method further includes prior tomoving the sample needle downward so the tip of the sample needletouches the bottom of the sample container: sensing, by the opticaldetection system, that a stripper foot is pressing upon a top of thesample container with a predetermined amount; and puncturing the top ofthe sample container with a puncture needle.

Additionally or alternatively, the determining the sample needle hasmoved the predetermined distance upward from the first position furthercomprises: sensing, by the optical detection system, that the stripperfoot is pressing upon the top of the sample container.

Additionally or alternatively, a spring operably attached to thestripper foot deflects a predetermined amount.

Additionally or alternatively, the method further includes using anencoder system in moving the sample needle and determining that the tipof the sample needle is in contact with the bottom of the samplecontainer.

Additionally or alternatively, the determining that the tip of thesample needle is in contact with the bottom of the sample containerfurther comprises: moving the sample needle a pre-specified aspirationdepth within the sample container; incrementally moving the sampleneedle downward toward the bottom of the sample container; anddetermining that an encoder output of a latter incremental step has notchanged relative to an encoder output of a prior incremental step.

Additionally or alternatively, the method further includes reducingcurrent in a motor controlling movement of the sample needle during theincremental moving the sample needle downward toward the bottom of thesample container.

Additionally or alternatively, the method further includes increasingthe current in the motor controlling movement of the sample needle afterthe determining that the tip of the sample needle is in contact with thebottom of the sample container.

Additionally or alternatively, the method further includes accountingfor a deflection of a sample platter upon which the sample containerrests caused by contact of the tip of the sample needle touching thebottom of the sample container, prior to the aspirating the sample inthe sample container.

Additionally or alternatively, the method further includes compensatingfor a relative position between the sample container and the sampleplatter in determining the predetermined distance upward.

Additionally or alternatively, a control system is configured to controlthe moving of the sample needle, the aspirating the sample, andconfigured to perform the determining that the tip of the sample needleis in contact with the bottom of the sample container and thedetermining that the sample needle has moved the predetermined distanceupward from the first position.

Additionally or alternatively, the sample needle is included in a sampleneedle carriage assembly that includes a stripper foot, puncture needleand separate drive motors for the sample needle and the puncture needle.

Additionally or alternatively, a distance between the tip of the sampleneedle and the bottom of the sample container is less than 1.1 mm priorto the aspirating the sample.

Additionally or alternatively, the method further includes minimizing aresidual volume to less than luL by ensuring the tip of the sampleneedle remains within 1.1 mm from the bottom of the sample containerprior during the aspirating the sample.

In accordance with another embodiment, a liquid chromatography systemconfigured to perform the method. The liquid chromatography systemincludes: a solvent delivery system; a sample manager having a thermalchamber; a sampling mechanism mounted within the thermal chamber, thesampling mechanism including a sample platter mounted in the thermalchamber, and a sample delivery system in fluidic communication withsolvent delivery system, the sample delivery system including the sampleneedle, the sample delivery system configured to transfer the samplefrom the sample container located in the sample platter into achromatographic flow stream; a liquid chromatography column locateddownstream from the solvent delivery system and the sample deliverysystem; and a detector located downstream from the liquid chromatographycolumn.

Additionally or alternatively, the liquid chromatography system furtherincludes a control system that is configured to control the moving ofthe sample needle, the aspirating the sample, and configured to performthe determining that the tip of the sample needle is in contact with thebottom of the sample container and the determining that the sampleneedle has moved the predetermined distance upward from the firstposition.

In accordance with another embodiment, a sample manager is configured toperform the method. The sample manager includes a thermal chamber; and asampling mechanism mounted within the thermal chamber, the samplingmechanism including a sample platter mounted in the thermal chamber, anda sample delivery system in fluidic communication with solvent deliverysystem, the sample delivery system including the sample needle, thesample delivery system configured to transfer the sample from the samplecontainer located in the sample platter into a chromatographic flowstream.

Additionally or alternatively, the sample manager includes a controlsystem that is configured to control the moving of the sample needle,the aspirating the sample, and configured to perform the determiningthat the tip of the sample needle is in contact with the bottom of thesample container and the determining that the sample needle has movedthe predetermined distance upward from the first position.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of this invention may be betterunderstood by referring to the following description in conjunction withthe accompanying drawings, in which like reference numerals indicatelike elements and features in the various figures. For clarity, notevery element may be labeled in every figure. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 depicts a schematic view of a liquid chromatography systemincluding a sample manager in accordance with one embodiment.

FIG. 2 depicts a perspective view of a liquid chromatography systemincluding the sample manager of FIG. 1 in accordance with oneembodiment.

FIG. 3 depicts a perspective view of an interior of the sample managerof FIGS. 1 and 2 , in accordance with one embodiment.

FIG. 4 depicts a perspective view of the interior of the sample managerof FIGS. 1 and 2 in a first calibration position, in accordance with oneembodiment.

FIG. 5 depicts a perspective view of the interior of the sample managerof FIGS. 1 and 2 in a second calibration position, in accordance withone embodiment.

FIG. 6 depicts a perspective view of a needle arm detached from aninterior of a sample manager, in accordance with one embodiment.

FIG. 7 depicts a perspective view of the needle arm of FIG. 6 with aneedle assembly detached, in accordance with one embodiment.

FIG. 8 depicts a side view of the needle arm of FIG. 6 , in accordancewith one embodiment.

FIG. 9 depicts a top view of the needle arm of FIGS. 6 and 8 , inaccordance with one embodiment.

FIG. 10 depicts a side cross sectional view of the needle arm of FIGS.6, 8 and 9 , taken at arrows 10-10 in FIG. 9 , in accordance with oneembodiment.

FIG. 11 depicts a perspective view of a needle arm with a needlemechanism base detached, in accordance with one embodiment.

FIG. 12 depicts an enlarged perspective view of a puncture needle andstripper foot of the needle arm of FIG. 11 , in accordance with oneembodiment.

FIG. 13 depicts an enlarged perspective view of the puncture needle andstripper foot of FIG. 12 with a sample needle extending through thepuncture needle, in accordance with one embodiment.

FIG. 14 depicts an enlarged perspective view of a portion of an opticalsensor system of the needle arm of FIG. 11 that is in an open state, inaccordance with one embodiment.

FIG. 15 depicts an enlarged perspective view of the portion of theoptical sensor system of the needle arm of FIG. 11 that is in a closedstate, in accordance with one embodiment.

FIG. 16 depicts a side cutaway view of the sample needle of FIG. 13within a sample container, in accordance with one embodiment.

FIG. 17 depicts a perspective cutaway view of the sample needle withinthe sample container of FIG. 16 , in accordance with one embodiment.

FIG. 18 depicts an exemplary method of aspirating a sample, inaccordance with one embodiment.

FIG. 19 depicts another exemplary method of aspirating a sample, inaccordance with one embodiment.

DETAILED DESCRIPTION

Reference in the specification to “one embodiment” or “an embodiment”means that a particular, feature, structure or characteristic describedin connection with the embodiment is included in at least one embodimentof the teaching. References to a particular embodiment within thespecification do not necessarily all refer to the same embodiment.

The present teaching will now be described in more detail with referenceto exemplary embodiments thereof as shown in the accompanying drawings.While the present teaching is described in conjunction with variousembodiments and examples, it is not intended that the present teachingbe limited to such embodiments. On the contrary, the present teachingencompasses various alternatives, modifications and equivalents, as willbe appreciated by those of skill in the art. Those of ordinary skillhaving access to the teaching herein will recognize additionalimplementations, modifications and embodiments, as well as other fieldsof use, which are within the scope of the present disclosure asdescribed herein.

The present invention will describe a system for aspirating a samplefrom a sample vial which allows for the sample needle to achieve a veryclose tip distance with a bottom of a sample needle. Methods describedherein may allow a liquid chromatography system, such as one of thesystems described herein, to obtain knowledge of an exact location of abottom of a sample container or vial, and thereby position the tip ofthe sample needle immediately proximate the bottom for aspiration of asample. More particularly, the tip may be configured to be located anexact predetermined distance from the bottom of the sample vial orcontainer during aspiration. While the present invention is described byreference to an exemplary liquid chromatography system with an exemplarysample chamber and sample platter arrangement, it should be understoodthat the inventive methodology described herein may be applied to anyliquid chromatography system.

In an exemplary embodiment, prior to performing a liquid chromatographyrun, a technician loads an array of vials containing samples onto asample-vial carrier, places the sample-vial carrier onto a drawer, andslides the drawer into a bay within a sample platter of a thermalchamber of a sample manager system. The sample manager system mayinclude a sample delivery system that is configured to transfer thesample from the sample-vial carrier into a chromatographic flow stream.The sample chamber may be a thermal chamber that includes a samplingmechanism which includes a rotating sample platter with improved samplecapacity and sampling accuracy. A sampling needle as a part of thesampling mechanism is located on a rotating needle arm that, incombination with the rotating sample platter, provides complete needlecoverage over the bays within the sample platter. While this particularform of needle arm provides good coverage of a sample platter and allowsa sample needle to interact with sample containers on any place abovethe platter, other platter and sample needle arrangements arecontemplated with various designs. The structure of the sample chamberand sample needle described herein is exemplary.

The features of the sample delivery system and sample manager thermalchamber described herein may be applicable to any liquid chromatographysystem configured to deliver samples into a chromatographic flow stream.As one example, FIG. 1 shows an embodiment of a liquid chromatographysystem 10 for separating a mixture into its constituents. The liquidchromatography system 10 includes a solvent delivery system 12 influidic communication with a sample manager 14 (also called an injectoror an autosampler) through tubing 16. The sample manager 14 is influidic communication with a chromatographic column 18. A detector 21for example, a mass spectrometer, is in fluidic communication with thecolumn 18 to receive the elution.

The solvent delivery system 12 includes a pumping system 20 in fluidiccommunication with solvent reservoirs 22 from which the pumping system20 draws solvents (liquid) through tubing 24. In one embodiment, thepumping system 20 is embodied by a low-pressure mixing gradient pumpingsystem having two pumps fluidically connected in series. In thelow-pressure gradient pumping system, the mixing of solvents occursbefore the pump, and the solvent delivery system 12 has a mixer 26 influidic communication with the solvent reservoirs 22 to receive varioussolvents in metered proportions. This mixing of solvents (mobile phase)composition that varies over time (i.e., the gradient).

The pumping system 20 is in fluidic communication with the mixer 26 todraw a continuous flow of gradient therefrom for delivery to the samplemanager 14. Examples of solvent delivery systems that can be used toimplement the solvent delivery system 12 include, but are not limitedto, the ACQUITY® Binary Solvent Manager and the ACQUITY® QuaternarySolvent Manager, manufactured by Waters Corp. of Milford, Mass.

The sample manager 14 may include an injector valve 28 having a sampleloop 30. The sample manager 14 operates in one of two states: a loadstate and an injection state. In the load state, the position of theinjector valve 28 is such that the sample manager loads the sample intothe sample loop 30. The sample is drawn from a vial contained by asample vial carrier. “Sample vial carrier” herein means any deviceconfigured to carry a sample vial such as a well plate, sample vialcarrier, or the like. In the injection state, the position of theinjector valve 28 changes so that the sample manager 14 introduces thesample in the sample loop 30 into the continuously flowing mobile phasefrom the solvent delivery system. The mobile phase thus carries thesample into the column 18. In other embodiments, a flow through needle(FTN) may be utilized instead of a Fixed-Loop sample manager. Using anFTN approach, the sample may be pulled into the needle and then theneedle may be moved into a seal. The valve may then be switched to makethe needle in-line with the solvent delivery system.

The liquid chromatography system 10 further includes a data system 34that is in signal communication with the solvent delivery system 12 andthe sample manager 14. The data system 34 has a processor 36 and aswitch 38 (e.g. an Ethernet switch) for handling signal communicationbetween the solvent delivery system 12 and sample manager 14, asdescribed herein. Signal communication among the various systems andinstruments can be electrical or optical, using wireless or wiredtransmission. A host computing system 40 is in communication with thedata system 34 by which a technician can download various parameters andprofiles (e.g., an intake velocity profile) to the data system 34.

FIG. 2 shows a perspective view of the liquid chromatography system 10including the sample manager 14, the detector 21, the chromatographiccolumn 18, the solvent delivery system 12, and the solvents 22. Each ofthe sample manager 14, the detector 21, the chromatographic column 18,the solvent delivery system 12 may include a housing or body withinwhich the various features may be housed, such as the data system 34,the sample loop 30 and injector valve 28, the pumping system 20, themixer 26 and the tubing 24. The various components 12, 14, 18, 19, 21,22 may be interconnected with fluidic tubes and in signal communicationto the data system 34 of the system. The liquid chromatography system 10is shown with the solvent delivery system 12, sample manager 14,chromatographic column 18, detector 21 and a tray for holding thesolvents 22 stacked together.

FIG. 3 depicts a perspective view of the sampling mechanism 100 of thesample manager 14 of FIGS. 1 and 2 , in accordance with one embodiment.As shown the sampling mechanism 100 includes a sample platter 110attached to datum base 112. A vertical frame 114 is attached and extendsperpendicular from the datum base 112. A needle arm 116 is attached tothe vertical frame 114. The needle arm 116 includes a puncture needle122 (shown in FIG. 4 ) and a sample needle (not shown) as part of asample delivery system that is in fluidic communication with the solventdelivery system 12. The sample needle may be configured to obtain orotherwise draw the sample from a sample vial. Thereafter, the sampledelivery system of the liquid chromatography system 10 is configured totransfer the sample into a chromatographic flow stream and to the column18 located downstream from the sample delivery system, and then to thedetector 21 located downstream from the column 18. The sample vial maybe one of many vials located within up to four sample vial carriers (notshown), located on the sample platter 110.

The sample platter 110 may be configured to rotate 360 degrees about afirst vertical axis A1 while the needle arm 116 is configured to atleast partially rotate about a second vertical axis A2. These tworotations may provide for sufficient coverage by the needle arm 116across all the sample vial carriers within the sample platter 110. Therotating needle arm 116, in combination with the rotation of the sampleplatter 110, may thereby be configured to move the sample needle 122into position to access any location on the sample platter 110 thatholds a sample vial within a sample vial carrier.

As shown, the sample platter 110 includes a circular frame that includesfour bays—a first carrier bay 126 a, a second carrier bay 126 b, a thirdcarrier bay 126 c, and a fourth carrier bay 126 d. The carrier bays 126a, 126 b, 126 c, 126 d are disposed equidistant about a perimeter of thecircular sample platter 110. In other words, the carrier bays, 126 a,126 b, 126 c, 126 d are disposed circumferentially 90 degrees from eachother about the circular sample platter 110. As described above, therotating needle arm 116, in combination with the rotation of the sampleplatter 110, is configured to move the sample needle 122 directly aboveany location covered by the respective perimeters of the respectivecarrier bays 126 a, 126 b, 126 c, 126 d. The platter can include fourbays as shown but may also include three bays or extended to even morethan four bays in other embodiments. The bays may be equidistant fromeach other or may be staggered in other manners about the circumferenceof the circular sample platter 110.

Each of the carrier bays 126 a, 126 b, 126 c, 126 d is shown as a drawerthat slides into and out of a bay drawer receiver 128 a, 128 b, 128 c,128 d. The carrier bays 126 a, 126 b, 126 c, 126 d may be configured tobe pulled from respective bay drawer receivers 128 a, 128 b, 128 c, 128d radially outwardly in order to facilitate ease of loading of samplevial carriers into and out a front door 130 of the sample platter (shownin FIG. 2 ). The integration of the carrier bays 126 a, 126 b, 126 c,126 d and the respective bay drawer receivers 128 a, 128 b, 128 c, 128 dmay be configured to stop the carrier bays 126 a, 126 b, 126 c, 126 dbefore the carrier bays 126 a, 126 b, 126 c, 126 d become fullydisconnected from the bay drawer receivers 128 a, 128 b, 128 c, 128 d.Alternatively, the bezel of the sampling mechanism 100 may include astructure that prevents the carrier bays 126 a, 126 b, 126 c, 126 d frombecoming fully disconnected from the bay drawer receivers 128 a, 128 b,128 c, 128 d.

The carrier bays 126 a, 126 b, 126 c, 126 d are each configured forreceiving sample vial carriers. The sample manager 100 may be configuredto receive and process samples within all four carrier bays 126 a, 126b, 126 c, 126 d. In addition to sliding in and out of the bay drawerreceivers 128 a, 128 b, 128 c, 128 d via a track system, the carrierbays 126 a, 126 b, 126 c, 126 d may include magnets positionedunderneath that are configured to magnetically retain the sample vialcarriers into position within the carrier bays 126 a, 126 b, 126 c, 126d. Corresponding magnets may be located a radially inward positionwithin the carrier bays 126 a, 126 b, 126 c, 126 d to further ensurethat the carrier bay 126 a, 126 b, 126 c, 126 d is in position properly(i.e. fully inserted) relative to the bay drawer receivers 128 a, 128 b,128 c, 128 d. Leaf springs 132 may be configured to bias received sampleplatters toward the left most wall of the respective carrier bays 126 a,126 b, 126 c, 126 d, while the magnetic structure retains the receivedsample platters against the radially inward wall of the respectivecarrier bays 126 a, 126 b, 126 c, 126 d.

The sample platter 110 includes a middle opening 134 for receiving apost 136 around which the sample platter 110 is configured to rotateabout the vertical axis A1. The sample platter 110 further includesadditional openings 136 disposed around the perimeter in between thecarrier bays 126 a, 126 b, 126 c, 126 d configured to receive and holdlarger single individual vials (not shown) or other samples. The needlearm 116 (and the needle thereof) may be configured to be positioned overeach of the perimeter additional openings 136.

The sample platter 110 is shown mounted to the datum base 112. The datumbase 112 may be a metallic plate that is mounted to a thermal chamberframe (not shown) within the sample manager 14. The datum base 112 mayinclude openings through which deflection limiting columns 120 extend.The deflection limiting columns 120 may be configured to preventdeflection of the sample platter 110 beyond a specific distance relativeto the datum base 112 before being stopped. The deflection limitingcolumns 120 may be keyed to a channel in the bottom of the sampleplatter 110 and may act as bearings to allow rotation of the sampleplatter 110 about the datum base 112. Rotation of the sample platter 110about the datum base 112 may be created by a motor 150 disposed on thedatum base 112 proximate the perimeter of the sample platter 110. Thedatum base 112 further includes a plurality of threaded openingsconfigured to receive bolts for attaching a right-angle bracket 118thereto at each side. The right-angle brackets 118 may be configured toattach the vertical frame 114 to the datum base 112 in a perpendicularorientation. An encoder (not shown) may further be attached to thesample platter 110 to maintain positioning of the sample platter 110relative to the datum base 112.

The vertical frame 114 is attached to the datum base 112 such that thevertical frame 114 extends through the circumference of the sampleplatter 110. To account for this location being over the sample platter110, the vertical frame 114 includes an opening 140 (shown in FIG. 4 )or cutout through which the sample platter 110 and any received samplevial carrier and any received sample vials are configured to pass. Theopening 140 is dimensioned tall enough to receive a tall sample vialcarrier without causing interference. The vertical frame 114 creates asurface over the opening 140 upon which to mount the needle arm 116.

The needle arm 116 is shown including a drive mechanism 142 and a motor144. The motor 144 is configured to rotate about an axis that rotates abelt 148, which in turn rotates a pulley 152. Rotation of the pulley 152may be configured to impart rotation of the needle arm 116 about thesecond vertical axis A2. The rotation of the needle arm 116 may beindependent rotation relative to the rotation of the sample platter 110,and may be rotation about a different vertical axis A2 than the verticalaxis A1 about which the sample platter 110 rotates.

Referring now to FIG. 4 , a perspective view of the interior of thesample manager 14 of FIGS. 1 and 2 is shown in a first calibrationposition, in accordance with one embodiment. The first calibrationposition shown in FIG. 4 is a position where the needle arm 116 isrotated counter clockwise about the second vertical axis A2 relative tothe position shown in FIG. 3 . As shown, a shaft 154 extends through thepulley 152 that is attached and configured to rotate with the pulley152. The shaft 154 is connected to a rotating plate 155 that isconfigured to rotate with the shaft 154 and impart rotation on a needleassembly 190. The shaft 154 includes a biasing spring 232. A removableneedle arm housing 158 is attached to the vertical frame 114. Theremovable needle arm housing 158 includes a horizontal plate 160extending from just above the opening 140 in the vertical frame 114. Thehorizontal plate 160 includes a bushing 156 configured to receive thebase of the shaft 154 and maintain the shaft 154 in alignment with thesecond vertical axis A2. The needle arm housing 158 is removablyattached to the vertical frame 114 with a plurality of accessible bolts162. The accessible bolts 162 are accessible through the door 130 of thesample manager 14. This may allow the entirety of the vertical frame 114and the needle arm 116 and all of the components thereof to be easilyremovable through the door 130 during maintenance or part replacement.

The needle arm 116 further includes a magnetic encoder 146. The magneticencoder 146 may be configured to determine rotational position of theneedle arm 116 to whatever tolerance is necessary for accuratepositioning of the sample needle 122. Likewise, the motor 150 may beequipped with an encoder for determining the rotational position of thesample platter 110. The two encoders in the system may be incommunication with a control system (e.g. data system 34) forcalibrating and controlling movement of the needle arm 116 and thesample platter 110. While magnetic encoders may be utilized, otherencoders are contemplated, such as optical encoders.

The needle arm 116 is shown including two separate motors 164 a, 164 bconfigured to rotate two separate drive shafts. A first motor 164 a isconfigured to rotate a first drive shaft 236 (shown in FIGS. 6 and 8 )that enacts movement on the puncture needle 122. A second motor 164 b isconfigured to rotate a second drive shaft 238 (shown in FIGS. 6 and 8 )that enacts movement on a sample needle (not shown). The first andsecond motors 164 a, 164 b may be attached to the needle arm 116 suchthat the motors 164 a, 164 b rotate with the needle arm 116. Thepuncture needle 122 may operate in conjunction with the sample needle inorder to puncture whatever material or membrane covers a sample vial.The two motors 164 a, 164 b may be configured to operate independentlyand may be controlled and programed by the control system and/or datasystem 34 for operational routines.

The needle assembly 190 of the needle arm includes a plate 192 havingtwo accessible bolts 194 which may be accessible by a technician thatopens the door 130 of the sample manager 14. Upon unbolting theaccessible bolts 194, the technician may remove the needle assembly 190and the attached motors 164 a, 164 b from the needle mechanism base 230.The needle assembly 190 and the motors 164 a, 164 b may be removablethrough the door 130 of the sample manager 14 without removing theneedle mechanism base 230. Similarly, the motors 164 a, 164 b may beeasily removed from the needle arm 116 by removal of one or moreaccessible motor bolts 196 from the plate 192. This may allow for themotors 164 a, 164 b to be easily replaced or removed for maintenancethrough the front door 130 of the sample manager 14 without removal ofother components of the needle arm 116.

The sample delivery system may further include a fluidic tube (notshown) located between the sample needle and the liquid chromatographycolumn 18. The fluidic tube may include a coiled portion configured toexpand and contract during rotation of the needle arm 116 about thesecond vertical axis A2. The coiled portion may extend between the topof the needle arm 116 above the puncture needle 122 and to the verticalframe 114. The coiled portion may uncoil when the needle arm 116 rotatesaway from the vertical frame 114 and recoils when the needle arm 116rotates toward the vertical frame 114. The coiled portion of the fluidictube may be spiraled, bent, or otherwise curled in order to provide forlengthwise expansion and contraction in a predictable manner that doesnot interfere with the other movement of the various components withinthe sample manager 14.

Referring back to FIG. 3 , the needle arm 116 is shown in this viewhaving been rotated to a home position, whereby a projecting stop 182that is connected to, coupled to, or integrated into, the vertical frame114 is contacted with the needle assembly 190. The home position may bea position that is rotated to a stopping point, past which the needlearm 116 may not be capable of rotating. As shown, at the home positionthe needle arm 116 is rotated in a clockwise direction to a point ofmaximum rotation whereby the needle arm 116 is stopped from furtherclockwise rotation by the projecting stop 182.

Attached to the datum base 112 may be a needle wash system (not shown)extending from an opening 170 located in the datum base 112 near thehome position or location. The needle wash system may include aplurality of liquid source tubes each configured to introduce waterand/or other cleaning agent(s) to wash the sample needle 122 and/or thepuncture needle when the needles are moved over the needle wash system.A wash process may include, for example, providing a first cleaningagent to the sample needle 122 from a first of the liquid source tubes,and then moving the sample needle 122 over the second of the liquidsource tubes to be cleansed with water. Other wash processes andstructure are contemplated as would be appropriate to wash needle(s) inthe needle arm 116.

The needle arm 116 may be configured to rotate about the rotating shaft154 and the second axis A2 an amount that allows complete coverage ofthe needle assembly 190 over the entirety of the working portion of thesample platter 110. The needle arm 116 may be configured to rotate morethan 45 degrees but less than 90 degrees in the embodiment shown.Additional rotational movement than what is shown (i.e. equal to orgreater than 90 degrees) is also contemplated in other embodiments.

Referring to FIGS. 4 and 5 , the interior of the sample manager 14 ofFIGS. 1 and 2 is shown with the needle arm 116 located in twocalibration positions, in accordance with one embodiment. In variouscontemplated embodiments, various calibration systems are contemplated.FIGS. 4 and 5 shown one exemplary calibration system in which the datasystem 34 and/or sample manager control system may be configured tocalibrate the sampling mechanism 100 to use. One calibration process mayinclude a first step, shown in FIG. 4 , of moving the sample platter 110and the needle arm 116 to align the needle with the first opening 210 inthe sample platter and then recording a first encoder position of eachthe sample platter 110 and the needle arm 116. For example, the needlearm 116 may move counter-clockwise from the home position (shown in FIG.3 ) to the position shown in FIG. 4 so that the puncture needle 122 (orsample needle) is directly above the first opening 210.

The calibration process may then include a second step of moving thesample platter 110 and the needle arm 116 to the position shown in FIG.5 , in order to align the puncture needle 122 (or sample needle) withthe second opening 220 in the sample platter. The calibration processmay then include recording a second encoder position of each the sampleplatter 110 and the needle arm 116. With the known first and secondencoder positions, the data system 34 and/or sample manager controlsystem may be configured to back-calculate the geometric parameters ofthe sampling mechanism 100 and thereby calibrate the movement andposition of the sample platter 110 and the needle arm 116. Thepositional accuracy may be more precise than a typical prior artcalibration process, as the inventive process described above does notrely on assumed geometric qualities being within a certain level oftolerance.

FIG. 6 depicts a perspective view of the needle arm 116 detached fromthe interior of the sample manager 14, in accordance with oneembodiment. As shown, the needle arm 116 includes a base 230 that isremovably attachable to the sample manager 14 of the liquidchromatography system 10. The needle arm 116 further includes the needleassembly 190 that is removably attachable to the base 230. Theremovability of each of the base 230 from the sample manager 14 and theneedle assembly 190 from the base 230 may be provided by accessiblebolts, screws, pins or other easily accessible, engageable and/ordisengageable coupling devices. The attachable removability of each ofthese components as described herein provides for ease of servicing andreplacing components of the needle arm 116 through a front door of thesample manager 14. Further, as described above, the needle arm 116includes sufficient structure to provide for rotational movement of thearm about a vertical axis when the needle arm 116 is attached within asample manager 14.

FIG. 7 depicts a perspective view of the base 230 of the needle arm ofFIG. 6 with the needle assembly 190 detached, in accordance with oneembodiment. The base 230 includes the removable needle arm housing 158.The removable needle arm housing 158 provides a frame for attaching thebase 230 to the interior of the sample manager 14 of the liquidchromatography system 10, such as by attachment of the removable needlearm housing 158 to the vertical frame 114. The removable needle armhousing 158 includes a flat vertical surface configured to abut the flatvertical surface of the vertical frame 114. As shown in FIG. 6 , aplurality of alignment pins 234 located on a back surface of the needlearm housing 158 act in cooperation with the accessible bolts 162 toattach the flat vertical surface of the needle arm housing 158 with theflat vertical surface of the vertical frame 114. While not shown, thevertical frame 114 may include corresponding bores, or female receivingopenings for receiving each of the accessible bolts 162 and alignmentpins 234.

As shown, the base 230 includes the shaft 154 that is configured torotate about the vertical axis A2. The removable needle arm housing 158is configured to hold the shaft 154 at both a top location and a bottomlocation, while allowing the shaft 154 to rotate about the removableneedle arm housing 158. Specifically, the removable needle arm housing158 includes the lower horizontal plate 160 and an upper horizontalplate 161 extending from the flat vertical surface of the removableneedle arm housing 158. The bushing 156 is disposed with an opening atthe lower horizontal plate 160 allowing the shaft 154 to rotate therein.

The base 230 further includes the motor 144, the drive mechanism 142,the belt 148, the pulley 152, and the rotating plate 155. The drivemechanism 142 of the motor 144 may be a drive shaft, or the like, thatthe motor 144 is configured to cause to rotate. Rotation of the drivemechanism 142 further causes movement of the belt 148 and therebyrotation of the pulley 152 that is attached to the vertical shaft 154.The rotating plate 155 is attached to the shaft 154, and is configuredto rotate with rotation of the shaft 154.

FIG. 8 depicts a side view of the needle arm 116 in accordance with oneembodiment including both the needle assembly 190 and the base 230.Referring to both the perspective view of FIG. 6 and the side view ofFIG. 8 , the base 230 is shown including each of the motor 144, themagnetic encoder 146, the housing 158 and the rotating plate 155. Theneedle assembly 190 includes a housing 264 or other body upon which thecomponents of the needle assembly 190 are attached. As shown, the plate192 of the housing 264 of the needle assembly 190 is attached to thebase 230, and specifically to the rotating plate 155.

The needle assembly 190 includes a drive system. The drive systemincludes a first motor having a first drive shaft 236 attached to a topof the plate 192 of the housing 264. The needle assembly 190 furtherincludes a second motor 164 b having a second drive shaft 238 attachedto a bottom of the plate 192 of the housing 264. The first motor 164 aand first drive shaft 236 are configured to impart vertical motion ormovement on the puncture needle 122 via imparting vertical motion ormovement on a puncture needle axis 260. Likewise, the second motor 164 band the second drive shaft 238 are configured to impart vertical motionor movement on a sample needle via imparting vertical motion or movementon a sample needle axis 258.

Further, a stripper foot 262 is attached to a stripper foot axis 268that includes a spring loaded end 266 having a spring mechanism. Thespring mechanism may be configured to compress during downward movementof the stripper foot 262 and stripper foot axis 268. In use, thestripper foot 262 may contact the top of a sample vial (not shown),after which the puncture needle 122 may be pushed through a protectivemembrane of the sample vial. After the puncture needle 122 has puncturedthis top protective membrane, the puncture needle 122 must be retractedfrom the sample vial and protective membrane. The stripper foot 262 maybe configured to provide a downward force on the top of the sample vialso that the puncture needle 122 may be retracted properly withoutsticking to the protective membrane of the sample vial. The stripperfoot 262 includes an opening through which the puncture needle 122 isconfigured to extend during puncturing.

As shown in FIG. 6 , the stripper foot axis 268 is movable relative tothe puncture needle axis 260, via two couplings 270. The couplings 270may include a top elongated vertical opening and a bottom elongatedopening in the stripper foot axis 268 through which top and bottomrespective pins extend. The top and bottom respective pins are attachedto a puncture needle coupling surface 272 of the puncture needle axis260. The top and bottom elongated vertical openings cooperate with thepins so that the stripper foot axis 268 and the puncture needle axis 260are connected or otherwise coupled in a manner that allows for verticalmovement between the stripper foot axis 268 and the puncture needle axis260. The maximum vertical movement between the stripper foot axis 268and the puncture needle axis 260 is defined by the vertical length ofthe top and bottom elongated vertical openings in the stripper foot axis268.

The sample needle is located along the same vertical axis as thepuncture needle 122. The sample needle may be a needle having a smallerdiameter than the puncture needle 122 such that the sample needle isconfigured to extend through the larger diameter opening of the punctureneedle 122. A needle holder 244 is located at a top of the sample needleaxis 258. The sample needle holder 244 may be configured to removablyreceive the sample needle at a location that aligns the sample needlewith the puncture needle 122. The sample needle holder 244 is attachedto the sample needle axis 258 so that the sample needle holder 244, andthereby the sample needle, move when the sample needle axis 258 isdriven or moved by the second motor 164 b and the second drive shaft 238thereof.

FIG. 9 depicts a top view of the needle arm 116, in accordance with oneembodiment. Referring to both the perspective view of FIG. 6 and the topview of FIG. 9 , a needle arm sensor system is shown. The sensor systemincludes a sample needle home sensor 240, a puncture needle home sensor252, and a top sensor 252. The sensor system may further include aprinted circuit board 246 configured to provide power, control signalsand/or communication signals to and from the various sensors 240, 254,252 in the sensor system. The printed circuit board 246 may be aflexible circuit board configured to flex with rotation of the needleassembly 190 about the vertical shaft 154. The printed circuit board 246may be capable of performing its function without losing its signaland/or conductive integrity while being bent back and forth through therotation of the needle assembly 190 about the vertical shaft 154throughout the lifecycle of the needle arm 116. The sensor system and/orprinted circuit board 246 and the sensors 240, 254, 252 may be inoperable communication with a control system such as the data system 34,such that sensed information is provided to the data system 34 forprocessing.

The sample needle home sensor 240 is configured to sense movement of thesample needle axis 258 and/or determine when the sample needle axis 258arrives in a home (top) position. The sample needle home sensor 240 maybe configured to sense and/or determine that the sample needle has beenmoved in a vertical direction a predetermined distance to a sampleneedle home position. The sample needle holder 244 is connected to thesample needle axis 258 and moves with the sample needle axis 258. Thesample needle holder 244 includes an extending projection 242 configuredto move between the two prongs of the sample needle home sensor 240.Thus, when the sample needle axis 258 moves to a top home position, theextending projection 242 is positioned between the two prongs of thesample needle home sensor 240, which thereby senses that the sampleneedle axis 258 is in the home position. A connecting conductor 248extends between the printed circuit board 246 and the sample needle homesensor 240 configured to provide power and/or other control orcommunication signals to and from the sample needle home sensor 240.

The puncture needle home sensor 252 is configured to sense movement ofthe puncture needle axis 260 and/or determine when the puncture needleaxis 260 arrives in a home (top) position. The puncture needle homesensor 252 may be configured to sense and/or determine that the punctureneedle 122 has been moved in a vertical direction a predetermineddistance to a puncture needle home position. The puncture needle axis260, and specifically the puncture needle coupling surface 272 thereof,includes an extending projection 256 configured to move between the twoprongs of the puncture needle home sensor 252. Thus, when the punctureneedle axis 260 moves to a top home position, the extending projection256 is positioned between the two prongs of the puncture needle homesensor 252, which thereby senses that the puncture needle axis 260 is inthe home position. A connecting conductor 248 extends between theprinted circuit board 246 and the puncture needle home sensor 252configured to provide power and/or other control or communicationsignals to and from the puncture needle home sensor 252.

The top sensor 254 of the sensor system is configured to sense when thestripper foot 262 is compressed by a predetermined amount. Thispredetermined amount may correspond to a force acting on the stripperfoot 262 by a top of the sample vial. A service loop 250 may extend fromthe printed circuit board 246 to the top sensor 254 for providing powerand/or other control or communication signals to and from the top sensor254. The top sensor 254 may be a stripper foot movement sensorconfigured to determine that the stripper foot 262 has been moved in avertical direction over a predetermined distance.

FIG. 10 depicts a side cross sectional view of the needle arm 116, inaccordance with one embodiment, taken at arrows 10-10 of FIG. 9 . Asshown, the drive system may include a system for converting therotational motion of the drive shafts 236, 238 to vertical linear motionof the axis 258, 260. The first and second motors 164 a, 164 b mayoperate independently from each other such that the puncture needle 122and a sample needle (not shown) are capable of independent verticalmotion. The top drive shaft 236 is shown extending from the first motor164 a through an opening in the plate 192 of the housing 264. Similarly,the bottom drive shaft 238 is shown extending from the second motor 164b through an opening in the plate 192 of the housing 264. As shown, thetop drive shaft 236 is attached to an engagement structure 274 that isconfigured to bypass the sample needle axis 258 and engage with thepuncture needle axis 260 to convert rotational motion of the drive shaft236 to linear vertical motion of the puncture needle axis 260.Similarly, the bottom drive shaft 238 is attached to an engagementstructure 276 that is configured to engage with the sample needle axis258 to convert rotational motion of the drive shaft 238 to linearvertical motion of the sample needle axis 258.

FIG. 11 depicts a perspective view of a needle arm 316 with the needlemechanism base detached (such as the needle mechanism base 230), inaccordance with one embodiment. The needle arm 316 may be the same orsimilar to the needle arm 116, described in detail hereinabove. Thus,the needle arm 316 includes a needle assembly 390 attached to twoseparate motors 364 a, 364 b configured to rotate two separate driveshafts. A first motor 364 a is configured to rotate a first drive shaft336 that enacts movement on a puncture needle 322. A second motor 364 bis configured to rotate a second drive shaft 338 that enacts movement ona sample needle 361 (shown in FIGS. 13, 16 and 17 ). The puncture needle322 may operate in conjunction with the sample needle 361 in order topuncture whatever material or membrane covers a sample vial or container400 (shown in FIGS. 16 and 17 ). The two motors 364 a, 364 b may beconfigured to operate independently and may be controlled and programedby a control system and/or data system, such as the control and/or datasystem 34 described hereinabove, for operational routines as describedherein and more particularly with respect to the methodology describedand shown in FIGS. 18 and 19 .

As shown in FIG. 11 , a stripper foot axis 368 is attached to a stripperfoot 362. The stripper foot axis 368 is movable relative to a punctureneedle axis 360, via two couplings 370. The couplings 370 may include atop elongated vertical opening and a bottom elongated opening in thestripper foot axis 368 through which top and bottom respective pinsextend. The top and bottom respective pins are attached to the punctureneedle axis 360. The top and bottom elongated vertical openingscooperate with the pins so that the stripper foot axis 368 and thepuncture needle axis 360 are connected or otherwise coupled in a mannerthat allows for vertical movement between the stripper foot axis 368 andthe puncture needle axis 360. The maximum vertical movement between thestripper foot axis 368 and the puncture needle axis 360 is defined bythe vertical length of the top and bottom elongated vertical openings inthe stripper foot axis 368.

Thus, the stripper foot 362 is attached to the stripper foot axis 368that includes a spring loaded end 366 having a spring mechanism. Thespring mechanism may be configured to compress during downward movementof the stripper foot 362 and stripper foot axis 368. In use, thestripper foot 362 may contact the top of a sample vial or container 400(shown in FIGS. 16 and 17 ), after which the puncture needle 322 may bepushed through a protective membrane of the sample vial. After thepuncture needle 322 has punctured this top protective membrane, thepuncture needle 322 must be retracted from the sample vial andprotective membrane. The stripper foot 362 may be configured to providea downward force on the top of the sample vial so that the punctureneedle 322 may be retracted properly without sticking to the protectivemembrane of the sample vial. The stripper foot 362 includes an openingthrough which the puncture needle 322 is configured to extend duringpuncturing.

The sample needle 361 is located along the same vertical axis as thepuncture needle 322. The sample needle 361 may be a needle having asmaller diameter than the puncture needle 322 such that the sampleneedle 361 is configured to extend through the larger diameter openingof the puncture needle 322. A needle holder 344 is located at a top of asample needle axis 358. The sample needle holder 344 may be configuredto removably receive the sample needle 361 at a location that aligns thesample needle with the puncture needle 322. The sample needle holder 344is attached to the sample needle axis 358 so that the sample needleholder 344, and thereby the sample needle 361, move when the sampleneedle axis 358 is driven or moved by the second motor 364 b and thesecond drive shaft 338 thereof.

The needle arm 316 includes an optical sensor system such as the sensorsystem of the needle arm 216 described hereinabove and shown in FIG. 9 .The sensor system includes a sample needle home sensor 340, a punctureneedle home sensor 352, and a top sensor 354. The sensor system mayfurther include a printed circuit board 346 configured to provide power,control signals and/or communication signals to and from the varioussensors 340, 354, 352 in the sensor system. The sensor system and/orprinted circuit board 346 and the sensors 340, 354, 352 may be inoperable communication with a control system such as the data system 34,such that sensed information is provided to the data system 34 forprocessing.

The sample needle home sensor 340 is configured to sense movement of thesample needle axis 358 and/or determine when the sample needle axis 358arrives in a home (top) position. The sample needle home sensor 340 maybe configured to sense and/or determine that the sample needle has beenmoved in a vertical direction a predetermined distance to a sampleneedle home position. The sample needle holder 344 is connected to thesample needle axis 358 and moves with the sample needle axis 358. Thesample needle holder 344 includes an extending projection 342 configuredto move between the two prongs of the sample needle home sensor 340.Thus, when the sample needle axis 358 moves to a top home position, theextending projection 342 is positioned between the two prongs of thesample needle home sensor 340, which thereby senses that the sampleneedle axis 358 is in the home position. A connecting conductor mayextend between the printed circuit board 346 and the sample needle homesensor 340 configured to provide power and/or other control orcommunication signals to and from the sample needle home sensor 340.

The puncture needle home sensor 352 is configured to sense movement ofthe puncture needle axis 360 and/or determine when the puncture needleaxis 360 arrives in a home (top) position. The puncture needle homesensor 352 may be configured to sense and/or determine that the punctureneedle 322 has been moved in a vertical direction a predetermineddistance to a puncture needle home position. The puncture needle axis360 includes an extending projection 356 configured to move between thetwo prongs of the puncture needle home sensor 352. Thus, when thepuncture needle axis 360 moves to a top home position, the extendingprojection 356 is positioned between the two prongs of the punctureneedle home sensor 352, which thereby senses that the puncture needleaxis 360 is in the home position. A connecting conductor extends betweenthe printed circuit board 346 and the puncture needle home sensor 352configured to provide power and/or other control or communicationsignals to and from the puncture needle home sensor 352.

The top sensor 354 of the sensor system is configured to sense when thestripper foot 362 is compressed by a predetermined amount. Thispredetermined amount may correspond to a force acting on the stripperfoot 362 by a top of the sample vial. A service loop 350 may extend fromthe printed circuit board 346 to the top sensor 354 for providing powerand/or other control or communication signals to and from the top sensor354. The top sensor 354 may be a stripper foot movement sensorconfigured to determine that the stripper foot 362 has been moved in avertical direction over a predetermined distance relative to thepuncture needle axis and/or the rest of the needle arm 316.

FIG. 12 depicts an enlarged perspective view of a puncture needle 322and stripper foot 362 of the needle arm 316 of FIG. 11 , in accordancewith one embodiment. The puncture needle 322 includes a receivinginterface 390 for engaging with the sample needle 361, as shown in FIG.13 . The stripper foot 362 is shown attached to the stripper foot axis368, while the puncture needle 322 is shown attached to the punctureneedle axis 360, each of which may be configured to move independently.As shown, a fluidic coupling 391 is included attachable such that a tube392 of the fluidic coupling 391 extends into the opening of the punctureneedle 322. The fluidic coupling 391 may be used to provide an inlet fora wash fluidic channel. The coupling 391 may allow for a tube (notshown) to be connected thereto and provide water or other wash fluid towash the outside of the sample needle 361 and the inside of the punctureneedle 322 in order to prevent sample carryover from one sample to thenext.

FIG. 13 depicts an enlarged perspective view of the puncture needle 322and the stripper foot 362 of FIG. 12 with the sample needle 361extending through the puncture needle 322, in accordance with oneembodiment. As described hereinabove, the sample needle 361 is connectedto the sample needle axis 358 which provides independent axial movementof the sample needle 361 relative to the puncture needle 322 and thestripper foot 362. The puncture needle 322 is attached to the punctureneedle axis 360 for independent movement. The puncture needle 322 andthe sample needle 361 are each independently motor driven, as describedhereinabove. In contrast, the stripper foot 362 is independently movableby movement of the stripper foot axis 362, but this movement is createdonly by upward force (or a removal thereof) on the stripper foot 362caused by the stripper foot acting upon a top of the sample container400.

FIG. 14 depicts an enlarged perspective view of a portion of the opticalsensor system of the needle arm 316 of FIG. 11 that is in an open state,in accordance with one embodiment. Similarly, FIG. 15 depicts anenlarged perspective view of the portion of the optical sensor system ofthe needle arm 316 of FIG. 11 that is in a closed state, in accordancewith one embodiment. As shown in FIGS. 14 and 15 , the top sensor 354 isconfigured to sense movement of the stripper foot 362 and/or thestripper foot axis 368 by an optical detector 355 which is capable ofdetecting when a flag 358 closes the sensor (when the stripper footexperiences upward pressure). The flag 358 is a thin structure whichextends from the stripper foot axis 368 such that when the stripper foot362 is compressed, the stripper foot axis 368 moves upward with the flag358, causing the top sensor 354 to become closed as shown in FIG. 15 .When the stripper foot 362 returns to an uncompressed state, the flag358 returns to the open (downward) or home position, as shown in FIG. 14. The top sensor 354 and the open and closed states thereof will bedescribed in detail herein below with respect to the methodologydescribed herein.

FIG. 16 depicts a side cutaway view of the sample needle 361 of FIG. 13within a sample container 400, in accordance with one embodiment. FIG.17 depicts a perspective cutaway view of the sample needle 361 withinthe sample container 400 of FIG. 16 , in accordance with one embodiment.As shown, the sample container 400 includes a chamber 402 within which asample may be contained. The chamber 402 of the sample container 400includes a bottom 401. The bottom 401 of the chamber 402 shown includesa conical bottom which extends to a nadir. However, the invention is notlimited to this embodiment, and any chamber dimensions are contemplated.In the position shown in FIGS. 16 and 17 , a tip 363 of the sampleneedle 361 is located a short distance D from the bottom 401 of thechamber 402. This may be an end position of the methodology describedherein below, after which the exact location of the bottom 401 of thechamber 402 is determined, and after which the sample needle is movedthe predetermined distance D above the bottom 401 so that the tip 363 ofthe sample needle 361 is extremely close but not touching the bottom 401of the chamber 402. As contemplated hereinbelow, it is possible to movethe sample needle 361 so that the tip 363 touches the bottom 401 of thechamber 402 and thereby causes some downward deflection on the sampleplatter 110 (shown hereinabove in FIGS. 3-5 ).

FIG. 18 depicts an exemplary method 500 of aspirating a sample, inaccordance with one embodiment. In accordance with the method 500, afirst step 502 includes moving a vial or container, such as thecontainer 400, into position relative to a sample aspiration system,such as the needle arm 316 or the needle arm 216. In order to accomplishthis first step, any type of sample movement may occur, such asautomatic movement of a sample platter in a sample chamber, such as thesample platter 110 of the sample manager 14. Similarly, the sampleaspiration system may also move, such as by rotating the needle arm 316as described herein.

The next step 504 of the method 500 includes engaging the stripper footwith a top of the vial, such that a detector determines that a stripperfoot is engaged. For example, this may be accomplished by the stripperfoot causing the flag 357 to close an optical sensor, such as the topsensor 354, as shown in FIG. 15 and described hereinabove. At thispoint, locations of various components of the needle arm 316 may betaken or marked by a control system, such as the data system 34. Forexample, the position of the puncture needle axis 360 as moved by thefirst motor 364 a may be noted, saved, or otherwise marked. Once thisposition is marked, a step 506 of the method 500 occurs, in which thevial is punctured by engagement with the puncture needle 322. In orderto accomplish step 506, the puncture needle axis 360 is moved evenfurther downward by the first motor 364 a.

At a next step 508, the puncture needle motor is configured to move up astripper foot positioning mechanism, such as the puncture needle axis366. This movement may be performed incrementally until pressure on thestripper foot 362 is released and the top sensor 354 is once again in anopen state. From here, the stripper foot positioning mechanism (i.e. thepuncture needle axis 366 in the embodiment shown hereinabove) is onceagain moved downward so that the top sensor 354 is once again blocked ata step 510 of the method 500. This moving back and forth afterpuncturing may be configured to re-determine a location under which thestripper foot 362 is under tension after the vial is punctured. Fromthis point where the top sensor 354 is once again blocked, the method500 may include a step 512 of applying by the system a furtherpredetermined amount of additional or further pressure by providing moredownward motion with the first motor 364 a on the puncture needle axis366. For example, the first motor 364 a may be configured to move 4additional steps down. This additional downward force may be configuredto place the sample platter 110 under tension by the force applied bythe stripper foot 362 on the sample container 400, the sample container400 on a sample container holder (not shown), and the sample containerholder onto the sample platter 110.

At this point in the method 500, the stripper foot 362 may be placing adownward force on the sample platter 110 in this manner. Any furtherdeflection of the sample platter later caused by pressing the tip 363 ofthe sample needle 361 onto the bottom 401 of the sample container 400will cause further deflection of the sample platter 110 and cause thestripper foot pressure to be reduced, thereby causing the top sensor 354to open once again, as shown in FIG. 14 .

From this position, the method 500 includes a step 514 of moving thesample needle 361 to a predetermined aspiration depth somewhere withinthe chamber 402. The aspiration depth at this stage may be a predictiveor guessed depth that gets the tip 363 of the sample needle 361 close tothe bottom 401 of the chamber 402. However, this aspiration depth maynot be precise or a fully known distance between the bottom 401 of thechamber 402 and the tip 363 of the sample needle 361. Once moved intothe chamber 402 by the sample needle 361 in this manner, a next step 516of the method 500 includes reducing current to the motor that moves thesample needle 361, such as the second motor 364 b as describedhereinabove.

With the current reduced, the method 500 includes a step 518 ofincrementally moving the sample needle 361 downward, by the second motor364 b. With each incremental motor current attempting to move the sampleneedle 361 taken in step 518, the encoder output is checked at a step520 to see if there has been an actual movement by the sample needle 361in the vertical direction. If there is movement, the current remains lowand the step 518 is repeated within another incremental move downwardfor the sample needle 361 attempted by the second motor 364 b. If thereis no movement detected and the encoder output is not greater than theprevious output (i.e. no downward movement of the sample needle 361)despite the attempt by the second motor 364 b to move the sample needle361, then a stall is registered by the system and the method 500 movesto the step 522 in which the current to the second motor 364 b is setback to standard.

At this point in the method 500, the stripper foot 362 has placed aninitial force on the sample vial causing a deflection in the sampleplatter 110 and putting the sample platter 110 under tension. Next, thesample needle 361 has been incrementally moved under low current to findthe bottom. The low current may be low enough that a touchdown of thetip 363 of the needle 361 to the bottom 401 of the sample container 400.This may release the tension on the stripper foot 362, thereby openingthe top sensor 354. Instead, the sample needle has replaced the sourceof the tension on the sample container 400 and thereby the sampleplatter 110. Thus, when the low current motor output of the second motor364 b does not produce movement of the sample needle 361, the system candetermine that the tip 363 of the sample needle 361 is at the bottom 401and is under the tension previously created by the stripper foot 362.

From this position, a step 524 includes incrementally moving up the tip363 of the sample needle 361 from the bottom 401 of the container 400until the top sensor 354 becomes closed once again, as shown in FIG. 15, due to the tension source being transferred from the tip 363 of thesample needle 361 back to the stripper foot 362. At the position the topsensor 354 becomes closed, the tip of the sample needle 361 may bebarely in contact or literally proximate the bottom 402 of the samplecontainer 400. From this point, the method 500 may include a step 526 ofincrementally moving the sample needle upward a predetermined distanceD. This predetermined distance may be an extremely small distanceconfigured to allow the needle to aspirate extremely close to the bottomof the sample container. For example, the predetermined distance may beless than 1.1 mm prior to the aspirating the sample. The method 500 thenincludes a step 528 of aspirating the sample from this predetermineddistance.

Advantages of the above-described method include always knowing youraspiration depth. This may be important in cases where a composition ofa sample may not be constant across its depth. Further, theabove-described method provide a method to get extremely close to abottom, but not touching the bottom, during aspiration. This may allowfor a greater amount of usable sample in a container, which isparticularly important when the container is not filled with sample, butrather the sample is smaller in size. Thus, the method provides a way toconsistently provided for less than 1 uL residual of sample afteraspiration, if needed.

FIG. 19 depicts another exemplary method 600 of aspirating a sample, inaccordance with one embodiment. The method 600 includes a first step 602of using an optical sensor in determining a starting position of thesample needle system relative the sample container. The method 600includes a second step 604 of sensing, by the optical detection system,that a stripper foot is pressing upon a top of the sample container witha predetermined amount, such as a predetermined distance or level offorce. The method 600 includes another step 606 of puncturing the top ofthe sample container with a puncture needle. The method 600 includes afurther step 608 of moving a sample needle downward to a first positionso a tip of the sample needle touches a bottom of the sample container.Still further, the method 600 includes a step 610 of determining thatthe tip of the sample needle is in the first position where the sampleneedle is in contact with the bottom of the sample container. The method600 includes a step 612 which occurs after the determining that the tipof the sample needle is in contact with the bottom of the samplecontainer. The step 612 includes incrementally moving the sample needleupward from the first position. The method 600 includes a next step 614of determining the sample needle has moved a predetermined distanceupward from the first position. The method 600 includes a next step 616of sensing, by the optical detection system, that the stripper foot ispressing upon the top of the sample container with the predeterminedamount of deflect. In other embodiments it may also be possible to sensethat the stripper foot is pressing upon the top of the sample containerwith a predetermined level of force. The method 600 finally includes astep 618 of aspirating a sample in the sample container after thedetermining the sample needle has moved the predetermined distanceupward from the first position.

While the invention has been shown and described with reference tospecific embodiments, it should be understood by those skilled in theart that various changes in form and detail may be made therein withoutdeparting from the spirit and scope of the invention as recited in theaccompanying claims.

What is claimed is:
 1. A method of aspirating a sample, the methodcomprising: moving a sample needle downward to a first position so a tipof the sample needle touches a bottom of the sample container;determining that the tip of the sample needle is in the first positionwhere the sample needle is in contact with the bottom of the samplecontainer; after the determining that the tip of the sample needle is incontact with the bottom of the sample container, incrementally movingthe sample needle upward from the first position; determining the sampleneedle has moved a predetermined distance upward from the firstposition; and after the determining the sample needle has moved thepredetermined distance upward from the first position, aspirating asample in the sample container.
 2. The method of claim 1, furthercomprising: before the moving the sample needle downward to the firstposition so the tip of the sample needle touches the bottom of thesample container, using an optical sensor in determining a startingposition of the sample needle system relative the sample container. 3.The method of claim 1, further comprising: using an optical detectionsystem in determining that the sample needle has moved the predetermineddistance upward from the first position.
 4. The method of claim 3,further comprising: prior to moving the sample needle downward so thetip of the sample needle touches the bottom of the sample container:sensing, by the optical detection system, that a stripper foot ispressing upon a top of the sample container with a predetermined amount;and puncturing the top of the sample container with a puncture needle.5. The method of claim 4, wherein the determining the sample needle hasmoved the predetermined distance upward from the first position furthercomprises: sensing, by the optical detection system, that the stripperfoot is pressing upon the top of the sample container.
 6. The method ofclaim 5, wherein a spring operably attached to the stripper footdeflects a predetermined amount.
 7. The method of claim 1, furthercomprising: using an encoder system in moving the sample needle anddetermining that the tip of the sample needle is in contact with thebottom of the sample container.
 8. The method of claim 7 wherein thedetermining that the tip of the sample needle is in contact with thebottom of the sample container further comprises: moving the sampleneedle a pre-specified aspiration depth within the sample container;incrementally moving the sample needle downward toward the bottom of thesample container; and determining that an encoder output of a latterincremental step has not changed relative to an encoder output of aprior incremental step.
 9. The method of claim 8, further comprising:reducing current in a motor controlling movement of the sample needleduring the incremental moving the sample needle downward toward thebottom of the sample container.
 10. The method of claim 9, furthercomprising: increasing the current in the motor controlling movement ofthe sample needle after the determining that the tip of the sampleneedle is in contact with the bottom of the sample container.
 11. Themethod of claim 1, further comprising: accounting for a deflection of asample platter upon which the sample container rests caused by contactof the tip of the sample needle touching the bottom of the samplecontainer, prior to the aspirating the sample in the sample container.12. The method of claim 11, further comprising: compensating for arelative position between the sample container and the sample platter indetermining the predetermined distance upward.
 13. The method of claim1, wherein a control system is configured to control the moving of thesample needle, the aspirating the sample, and configured to perform thedetermining that the tip of the sample needle is in contact with thebottom of the sample container and the determining that the sampleneedle has moved the predetermined distance upward from the firstposition.
 14. The method of claim 1, wherein the sample needle isincluded in a sample needle carriage assembly that includes a stripperfoot, puncture needle and separate drive motors for the sample needleand the puncture needle.
 15. The method of claim 1, wherein a distancebetween the tip of the sample needle and the bottom of the samplecontainer is less than 1.1 mm prior to the aspirating the sample. 16.The method of claim 15, further comprising minimizing a residual volumeto less than 1 uL by ensuring the tip of the sample needle remainswithin 1.1 mm from the bottom of the sample container prior during theaspirating the sample.
 17. A liquid chromatography system configured toperform the method of claim 1, the liquid chromatography systemcomprising: a solvent delivery system; a sample manager having a thermalchamber; a sampling mechanism mounted within the thermal chamber, thesampling mechanism including a sample platter mounted in the thermalchamber, and a sample delivery system in fluidic communication withsolvent delivery system, the sample delivery system including the sampleneedle, the sample delivery system configured to transfer the samplefrom the sample container located in the sample platter into achromatographic flow stream; a liquid chromatography column locateddownstream from the solvent delivery system and the sample deliverysystem; and a detector located downstream from the liquid chromatographycolumn.
 18. The liquid chromatography system of claim 17, furthercomprising: a control system that is configured to control the moving ofthe sample needle, the aspirating the sample, and configured to performthe determining that the tip of the sample needle is in contact with thebottom of the sample container and the determining that the sampleneedle has moved the predetermined distance upward from the firstposition.
 19. A liquid chromatography sample manager configured toperform the method of claim 1, comprising: a thermal chamber; and asampling mechanism mounted within the thermal chamber, the samplingmechanism including a sample platter mounted in the thermal chamber, anda sample delivery system in fluidic communication with solvent deliverysystem, the sample delivery system including the sample needle, thesample delivery system configured to transfer the sample from the samplecontainer located in the sample platter into a chromatographic flowstream.
 20. The liquid chromatography sample manager of claim 19,further comprising: a control system that is configured to control themoving of the sample needle, the aspirating the sample, and configuredto perform the determining that the tip of the sample needle is incontact with the bottom of the sample container and the determining thatthe sample needle has moved the predetermined distance upward from thefirst position.